Fix to Body Overflow in Firefox on Windows

When the GameOn site is viewed on Firefox (at least in Windows), the window overflows to the right with a scrollbar, even though there isn't actually any content hanging over.  I've seen this happen before in Firefox, and I usually fix it by adding overflow-x: hidden to the body, which I have done here.
![screenshot - 6_7_2013 7_05_05 pm](https://f.cloud.github.com/assets/3675357/626641/53e32c12-cfc7-11e2-846c-f4b1738383f1.jpg)